Hydraulic door lock for horizontal baler



July 30, 1963 IL. B. LOVRINCH 3,099,205

' HYDRAULIC DOOR LOCK FOR HORIZONTAL BALER Filed Nov. 16, 1962 4 Sheets-Sheet 1 IN VEN TOR.

LOU/J 8. oVel/vCH y 1963 L. B. LOVRINCH 3,099,205

HYDRAULIC DOOR LOCK FOR HORIZONTAL BALER Filed Nov. 16, 1962 4 Sheets-Sheet 2 i INVEN TOR.

A OU/J 8. 4 a VFI VCAI BY WPWWW *gmm y 1963 B. LOVRINCH 3,099,205

HYDRAULIC DOOR LOOK FOR HORIZONTAL BALER Filed Nov. 16, 1962 4 Sheets-Sheet 3 N P F INVENTOR.

LOU/J 8. LOV/Ql/VC'H 1 BY 4 7" roe/vs PS July 30, 1963 1.. B. LOVRINCH HYDRAULIC DOOR LOCK FOR HORIZONTAL BALER Filed Nov. 16, 1962 4 Sheets-Sheet 4 INVENTOR. laws 8- Z a VE/NCH A TTOE/VE VS trimmings, waste textile material, and the like.

States This application is a continuation-in-part of my previously filed copending application Serial No. 89,963, filed February 17, 1961 (now abandoned), and entitled Hydraulic Door Lock for Horizontal Baler.

This invention relates to material handling devices, and more particularly to horizontal baling devices provided with releasable closures.

A main object of the invention is to provide a novel and improved door controlling and operating means for a horizontal hydraulically operated baling machine of the type employed for use in compressing and baling materials, such as waste paper, waste cardboard, light gauge metal trimmings, textile materials, and the like.

A further object of the invention is to provide an improved door locking and opening device for the end door of a hydraulic baling machine, said device being simple in construction, being easy to operate, and providing safe controlled opening of the door of the machine Whenever required.

A still further object of the invention is to provide an improved hydraulically operated door locking and opening apparatus for a hydraulic baling machine, said apparatus involving inexpensive components, being reliable in operation, being easy to control, and having means to provide a retarded opening action for its door which prevents the door from being swung open so suddenly that it might cause injury or damage.

Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein:

FIGURE 1 is a perspective view of the end portion of a horizontal hydraulically operated baling machine provided with an end door controlled by an improved locking and opening apparatus constructed in accordance with the present invention.

FIGURE 2 is an enlarged horizontal cross sectional view taken substantially on the line 22 of FIGURE 1.

'FIGURE 3 is an enlarged fragmentary perspective view of the door locking and opening apparatus employed in the device shown in FIGURES l and 2 with the door in locked position.

FIGURE 4 is an enlarged horizontal cross sectional view taken substantially on the line 44 of FIGURE 3.

FIGURE 5 is a vertical cross sectional view taken substantially on the line 55 of FIGURE 4.

FIGURE 6 is an enlarged perspective view showing the end portions of the door locking and opening device illustrated in FIGURES l to 5, the parts of the device being shown in separated positions.

FIGURE 7 is a schematic diagram showing the 11ydraulic connections of the baling machine of FIGURE 1 and illustrating the connections provided therein for the door locking and opening apparatus of the present invention.

FIGURE 8 is a schematic diagram similar to FIGURE 7 but illustrating a modification of the door locking and opening apparatus of the present invention.

Referring to the drawings, 11 generally designates a hydraulic baling machine of the horizontal type which is adapted to be employed in compressing and baling various waste materials, such as waste paper, waste cardboard in the form of cartons or other objects, light gauge metal Such ice material is formed into generally rectangular bales bound with wire or similar binding material. As shown in FIG- URE 1, the machine is arranged horizontally, the material to be baled being supplied thereto from the right end of the device, and suitable hydraulic ram means being provided to compress the material so that it is of substantial density, after which the material is bound by baling wire or similar binding material. Thus, the apparatus 11 comprises a frame 12 which includes longitudinally extending, vertically spaced generally channel-shaped bars 13 which are suitably supported in fixed positions, as by being secured to rectangular peripheral ring members 14 of substantial strength. The binding material is arranged so that it can be manipulated between the adjacent longitudinal bars 13 so as to be tied around the compressed material in the machine when such material has been compressed to the desired density. Thus, the binding material may be first disposed in the apparatus before the material to be compressed is compacted, so that the ends of the binding material will be accessible for tying after the pressure has been applied to the material to be baled.

The apparatus 11 is provided with the hinged end door 15 which is supported for swinging movement around a vertical axis defined by the hinge units 16, 16 provided at one side edge of the door and mounted on the adjacent vertical corner of the apparatus 11 adjacent the rearmost rectangular frame ring element 14, as shown in FIGURE 2. Obviously, the door 15 must be retained in closed position during the operation of the ram member, namely, when the waste material is being compressed in the frame 12, and for this purpose the free vertical edge of the door is provided at its intermediate portion with a locking bracket 17 having a pair of parallel, horizontally extending, vertically spaced, outwardly projecting locking fingers 18, 18. As shown in FIGURE 4, each finger 18 has a transversely extending outer edge 19, the reduced outer end portion 20 and the inclined inner edge portion 21 leading to said reduced outer end portion 28).

Designated at 22 is a horizontally arranged hydraulic cylinder which is mounted on the forward face of the vertical portion 23 of the rearmost rectangular ring member 14 in alignment with the bracket 17, the cylinder 22 being provided with a piston 25 having a piston rod 26 which extends slidably through the vertical frame member 23. A bifurcated head 27 is secured on the end of the piston rod 26, and rotatably connected to the head 27 between the vertically spaced arms 28, 28 thereof is a latch arm 29, the latch arm 29 being pivoted between the arms 28, 28 by a vertical pivot pin 30 which is engaged through vertically aligned apertures 31, 31 in the arms 28, 28 and through a pivot opening 32 in the latch arm 29. The pivot pin 30 is formed with a loop adjacent passage 33 which connects the intermediate portion of its outer vertical surface with a grease fitting 34 mounted in the top end of the pin, so that lubricant maybe applied to the bearing surfaces of the pivot pin 30. A vertical latch pin 35 is secured in the outer end portion of the latch arm 29, said latch pin 35 extending above and below the arm 29, as shown in FIGURE 6, and being lockingly engageable against the rear edge portions 19 of the locking fingers 18, 18 in the manner illustrated in FIGURES 4 and 5.

As shown in FIGURE 5, the pivot pin 30 is provided with an outwardly projecting top supporting flange 37 and may be upset at its bottom end, as shown at 38, so as to prevent its upward movement after it has been installed.

The vertical pin member '35 is of substantial height and rises a substantial distance above the upper finger 18 so that the arm 29 may be manually rotated at times, for example, to move same from the dotted view position shown in FIGURE 4 to the full line position thereof so as to lockingly engage against the edge portions '19 of the reduced ends 20, 20 \of the fingers 18, 18 when the door is looked after being swung into closed position preliminary to compacting a mass of Waste material in the baling machine.

As will be readily apparent from FIGURE 4, when the piston rod 26- is extended, for example, by the admission of hydraulic fluid under pressure into the end of cylinder '22 remote from the piston rod, the arcuately curved end edges of the lugs 28, 23, shown at 39, 39 engage against the lugs and cause the door 15 to swing towards its open position. Sufiicent clearance is provided between the arcuately curved edges 39, 39 and the vertical locking pin to allow the lugs 20, 26 to slip out from between pin 35 and arms 28, 28 as the piston rod '26 is extended. At the same time, the extension of the piston rod provides the necessary force to swing the door 15 to an open position, for example, the position shown in dotted view in FIGURE 2. The opening of the door 15 allows a compacted and tied bale of material, shown in dotted view at ll in FIGURE 2, to be expelled from the machine, for example, by operating the ram with a further mass of material to be baled inserted in the machine.

Referring to FIGURE 7, the ram of the machine is designated at 41 and is connected to the end of the piston rod 42 of a piston 43 contained in the main compacting cylinder 44. A motor driven pump 45 is employed to develop the required hydraulic pressure. As shown in FIGURE 7, the intake port of the pump 45 communicates with a hydraulic fluid reservoir 46 through a conduit 47. The high pressure outlet conduit of the pump 45 is designated at 48. A relief vent valve 45 is connected to the high pressure line 48 to limit the hydraulic pressure therein to a predetermined value, for example, 1500 pounds per square inch.

A conduit 50 connects the high pressure line 48 to the end of cylinder 22 adjacent the door :15 through a check valve 51, a conduit 52 and a restriction 53. The opposite end of cylinder 22 is connected to conduit 52 by a conduit 54 and a manually operated valve 55. Conduit 54 is connected to a return line 56 through a restriction 57, the return line 56 leading to the hydraulic fluid reservoir 46.

As will be apparent from FIGURE 7, hydraulic fluid is normally provided through check valve 51 and the restriction 53 to the end portion of cylinder 22 adjacent the door 15 so as to normally exert a retracting force on the piston rod 26. By opening the valve the hydraulic fluid under maximum pressure may be admitted to the opposite end of cylinder 22, pressure being allowed to build up in the conduit 54 by the presence of the restriction 57 in the adjacent return line 56, so that the hydraulic fluid under maximum pressure is exerted against the piston 25, causing the piston to discharge the hydraulic fluid in the opposite end portion of the cylinder, namely,

the portion adjacent the door 15, back through the conduit 52 through the restriction 53 at a controlled rate, the return fluid passing through the valve 55 and the conduit 54 into the end of cylinder 22 remote from the door 15, so as to merge with the high pressure hydraulic fluid to extend the piston rod 26. The presence of the restriction 53 serves not only to allow the high pressure to be developed in the conduit 54 when valve 55 is opened, but also retards the return of the hydraulic fluid from the portion of cylinder 22 adjacent the door 15 so as to prevent the piston rod 26 from being expended too rapidly, and so as to provide a retarded opening action which prevents the door 15 from being swung open so suddenly that it might cause inpury or damage.

As previously explained, when valve 55 is closed, fluid under maximum pressure is admitted through the restriction '53 and the check valve 51 into the end portion of the cylinder 22 adjacent the door 15 so as to retract the piston rod 26.

To lock the door 15, it is first moved to closed position and the arm 29 is then rotated from its dotted view position of FIGURE 2 towards its closing position, namely, toward a position such that the pin 35 is disposed adjacent the edge portions 19 of the fingers 18, 18, namely, to the full line position thereof illustrated in FIGURE 4. This operation may be performed with the piston 25 in such a position in the cylinder 22 that the pin 35 will clear the edge portions 19, 19. Thus, the valve 55 may be partially opened so as to counterbalance the pressures on the opposite sides of piston 25. However, when the door is to be locked, the valve 55 is closed, allowing maximum pressure to build up in the portion of cylinder 22 adjacent the door 15, whereby the piston rod 2-6 is retracted and the locking pin 35 exerts locking force on the edge portions 19, 19 of lugs 18, 18.

As shown in FIGURE 7, the hydraulic circuit of the machine includes a solenoid-operated relay valve 60 which controls respective operating cylinders 61 and 62 associated with the main hydraulic fluid control valve 63. A solenoid 64 controls the application of hydraulic fluid to the cylinder 44 for the power stroke of the ram 41 and a reverse solenoid 65 controls the retraction of the hus, when the solenoid 64 is energized the valve 60 is operated to move a pair of passages 66 and 67 respectively into positions to connect a pair of conduits 68, 69', and a pair of conduits 7t), 71. Conduit 68 is connected to the high pressure conduit 48 and conduit 76 is connected to the hydraulic fluid return line 72. Conduit 69 is connected to the relay cylinder 61 and conduit 71 is connected to the relay cylinder 62. Thus, the energization of solenoid 64 connects conduits 68 and 69, operating the relay cylinder 61 and at the same time allowing the relay cylinder 62 to exhaust through return line 72.

The operation of the relay cylinder 61 moves a pair of passages 73 and 74 in the slide member of valve 63 into positions to connect a pair of conduits 7'5, 76 and a pair of conduits 77, 78. Conduit 76 is connected to the high pressure line 48 and conduit 75 is connected to the end of cylinder 44 opposite the ram 41, so that high pressure hydraulic fluid is admitted into said end of the cylinder to provide the pressure stroke of the ram. At the same time the hydraulic fluid on the opposite side of the piston 43 is allowed to return through a conduit 79 and a check valve 80 to the line 76 so as to join with the hydraulic fluid under pressure acting against the piston 43 to develop the power stroke of the ram. A pressure relief valve 82 is connected to the line 79 to limit the pressure in said line.

The reverse action takes place when the solenoid 65 is energized. When this is done, the slide member of the valve 60 is moved to bring a pair of passages 84 and 85 into positions to respectively connect conduits 68 and 71 and conduits 70 and 69. The high pressure fluid flows from the conduit 68 through the passage 84 and the conduit 71 into the relay cylinder 62, causing the slide member of the valve 63 to be moved to the right, as viewed in FIGURE 7, to move a pair of passages 88 and 89 into positions so that the conduit 75 is connected to the conduit 78 through the passage 88 and the conduit 77 is connected to the conduit 76 through the passage 89. The high pressure fluid from the conduit 76 is thus admitted through a check valve 90 in the conduit 77 to the conduit 79 and into the cylinder 44 to act on piston 43 and to retract the ram 41. At the same time the hydraulic fluid in the end of the cyilnder 44 remote from the ram 4- 1 is allowed to exhaust through conduit 75, passage 88, conduit 78 and return line 72, leading to the hydraulic fluid reservoir 46. With the hydraulic ram 41 retracted, the door .15 may be unlocked in the manner above described, namely, by opening the valve 55, causing the piston 25 to be moved in a direction to extend the piston rod 26 and to open the door 15 at :a retarded rate, the retarded rate being in accordance with the size of the restricting orifice 53.

It will be noted that under normal conditions, both relay cylinders 61 and '62 are ineffective, since these cylinders are connected through a passage 92 in the valve 60 to the line 70 connected to the return line 72. Under these conditions the line 76 is connected to the line 78 through a restriction 93 in the valve 63 which allows a substantial pressure to be developed in the line 50. It will be noted that the restriction 93 is located in a passage 94 in the valve 63 which connects the line 76 to the return line 73. However, the restriction 93 is of such size as to allow a substantial pressure to be developed in the line 59, such pressure being suflicient to operate the locking cylinder 22.

As previously mentioned, various types of waste materials, such as paper trim, corrugated cardboard trim, boxboard trim, corrugated cartons, miscellaneous paper waste or paper products, light gauge metal trimmings, textile materials and other materials of the same general type may be compressed and baled by the apparatus. The materials are fed into a suitable loading hopper, not shown, which admits the materials into the compression chamber, for example, through an opening 96 in the top of the chamber, the materials being fed to the loading hopper either by hand or by suitable conveyor means. After the hopper has filled the chamber, the ram is actuated to pack the material in the chamber, the ram being retracted and additional material being fed into the chamber, so that after a number of strokes, the material may be compacted to define a bale of size suitable size and density. With the material thus compressed, the bale is tied by means of baling wire, twine, or other suitable strapping material, the tying material being passed around the bale through the slots provided in the sides of the baling chamber and through the slots defined between the cleats, shown at 97, of the ram 41. Ejection of the bale may be accomplished by opening the door 15, namely, by opening valve 55 to allow the door to open. The door is left open and production of a new bale is started following the same procedure above described. As the new bale progresses into the baling chamber, it pushes out the previously formed bale. After a series of strokes, the previously formed bale will be completely ejected from the baling chamber, and will be received on a suitable support, for example, on a conveyor, so that it can be moved away from the apparatus. The door can then be locked to allow the next bale to be formed.

in the form of the invention illustrated in FIGURE 8, the hydraulic circuit is generally the same as in FIGURE 7, except that the relief valve '82 is connected directly to the line 77 rather than to the line 7 9, so that the pressure of the operating fluid in line 77 is relieved and held below a limiting safe value, for example, 500 lbs. per square inch, before it passes through the check valve 90 and the conduit 79 to the right end of the cylinder 44.

The system of FIGURE 8 also omits the restriction in the line 52 between the right end of the cyilnder 22 and the connection to the branch containing the manually operated valve '55. Thus, the right end of the cylinder 22 is connected by a conduit portion 98 to the branch connection 99 containing the manually operated valve 55. With this arrangement, when valve 55 is closed, the high pressure fluid from line '52 will be admitted to the right end portion of cylinder v22, moving the piston 25 toward the left end of the cylinder and retracting the piston rod 26, providing the locking force of locking pin 35 on the edge portions 19, 19 of lugs 18, 18, as previously described. When valve 55 is opened, the return flow of fluid from the right end portion of cylinder 22 will be retarded by the restriction 57 in the fluid return line 56, the building up of pressure in the left end of the cylinder 22 taking place as in the previously described form of the invention. The fluid pressure developed in the left end portion of the cylinder 22 provides sufficient force to eventually extend the piston rod 26 because of the greater effective working area at the left side of piston 25 as compared with its working are-a at its right side. The working area of the piston 25 at its right side is reduced because of the presence of the piston rod 26. The difference between the working areas on the opposite sides of the piston 25, in combination with the retarding action provided by the restriction 57 to return flow of fluid provides relatively slow extension of the piston rod 26 and therefore provides a retarded release of the door 15.

It will be noted that the restriction 57 and the diameter of the piston rod 26 may be so designed that the resultant force acting to move the piston 25 to the right, namely, to release the door 15, is relatively small, and is merely sufficient to provide a slow extension of the piston rod 26.

While certain specific embodiments of an improved hydraulically operated baling press and a door locking system therefor have been disclosed in the foregoing description, it will be understood that various modifications within the spirit of the invention may occur to those skilled in the art. Therefore, it is intended that no limitations be placed on the invention except as defined by the scope of the appended claims.

What is claimed is:

1. In a baling apparatus, a horizontal baling chamber including a horizontally movable ram and fluid pressure means to exert inward force on said ram to compress material in said chamber, a door hinged vertically to the end of the chamber, a longitudinally extending fluid pressure cylinder secured horizontally to the side of the chamber opposite the hinged edge of the door, a piston in said cylinder having an externally projecting piston rod, said piston rod having an exposed end, a locking arm pivoted to said exposed end of said piston rod, a locking bracket on the firee vertical edge of the door lockingly engageable by said locking arm, a source of fluid pressure, a fluid pressure line connected to said source, a fluid return line, conduit means including a first restriction connecting said fluid pressure line to the end of said cylinder adjacent the door, conduit means including a manually operated valve connecting said flui'd pressure line to the opposite end of said cylinder, and conduit means including a second restriction connecting said opposite end of the cylinder to said fluid return line, said restrictions offering equal resistance to flow there through in either direction, whereby with said valve open, outward movement of said piston rod will be retarded because of the resistance to return flow of fluid from said cylinder through said first-named conduit means caused by said first restriction, thereby preventing sudden release of said locking arm.

2. In a baling apparatus, a horizontal baling chamber including a horizontally movable ram and fluid pressure means to exert inward force on said ram to compress material in said chamber, a door hinged vertically to the end of the chamber, a longitudinally extending fluid pressure cylinder secured horizontally to the side of the chamber opposite the hinged edge of the door, a piston in said cylinder having an externally projecting piston rod, said piston rod having an exposed end, a locking arm pivoted to said exposed end of said piston rod, a locking bracket on the free vertical edge of the door lockingly engageable by said locking arm, a source of fluidpressure, a fluid pressure line connected to said source, a fluid return line, conduit means including a check valve and a first restriction connecting said fluid pressure line to the end of said cylinder adjacent the door, conduit means including a manually operated valve connecting a point on said fluid pressure line between said check valve and said restriction to the opposite end of said cylinder, and conduit means including a second restriction connecting said opposite end of the cylinder to said fluid return line, said restrictions offering equal resistance to flow therethrough in either direction, whereby, with said valve open, outward movement of said piston rod will be retarded because of the resistance to return flow of fluid from said cylinder through said first-named conduit means caused by said first restriction, thereby preventing sudden release of said locking arm.

3. In a baling apparatus, a horizontal baling chamber incluing a horizontally movable ram and fluid pressure means to exert inward force on said ram to compress material in said chamber, a door hinged vertically to the end of the chamber, a longitudinally extending fluid pressure cylinder secured horizontally to the side of the chamber opposite the hinged edge of the door, a piston in said cylinder having an externally projecting piston rod, said piston rod having an exposed end, bracket means on the free vertical edge of said door, said bracket means including a pair of spaced horizontal locking lugs having transversely extending outer edge portions, a locking arm pivoted to said exposed end of said piston rod and being receivable between said locking lugs, vertical abutment means on said locking arm engageable with the outer edge portions of the locking lugs to lock said door when the piston is retracted in said cylinder, a source of fluid pressure, a fluid pressure line connected to said source, a fluid return line, conduit means including a first restricrtion connecting said fluid pressure line to the end of said cylinder adjacent the door, conduit means including a manually operated valve connecting said fluid pressure line to the opposite end of said cylinder, and conduit means including a second restriction connecting said opposite end of the cylinder to said fluid return line, said restrictions offening equal resistance to flow the-rethrough in either direction, whereby, with said valve open, outward movement of said piston rod will be retarded because of the resistance to return flow of fluid from said cylinder through said first-named conduit means caused by said first resuiction, thereby preventing sudden release of said locking arm.

4. In a baling apparatus, a horizontal bvali-n-g chamber including a horizontally movable ram and fluid pressure means to exert inward force on said ram to compress material in said chamber, a door hinged vertically to the end of the chamber, a longitudinally extending fluid pressure cylinder secured horizontally to the side of the chamber opposite the hinged edge of the door, a piston in said cylinder having an externally projecting piston rod, said piston rod having an exposed end, bracket means on the free vertical edge of said door, said bracket means including a pair of spaced horizontal locking lugs having transversely extending outer edge portions, a locking arm pivoted to said exposed end of said piston rod and being receivable between said locking lugs, vertical abutment means on said locking arm engageable with the outer edge portions of the locking lugs to lock said door when the piston is retracted in said cylinder, a source of fluid pressure, a fluid pressure line connected to said source, a fluid return line, conduit means including a check valve and a first restriction connecting said fluid pressure line to the end of said last-named cylinder adjacent the door, conduit means including a manually operated valve connecting a point on said fluid pressure line between said check valve and said restriction to the opposite end of said lastnamed cylinder, and conduit means including a second restriction connecting said opposite end of the last-named cylinder to the fluid return line, said restrictions offering equal resistance to flow therethrough in either direction, whereby, with said valve open, outward movement of said piston rod will be retarded because of the resistance to return flow of fluid from said cylinder through said firstnamed conduit means caused by said first restriction, thereby preventing sudden release of said locking arm.

5. In a haling apparatus, a horizontal .baling chamber including a horizontally movable ram and fluid pressure means to exert inward force on said ram to compress material in said chamber, a door hinged vertically to the end of the chamber, a longitudinally extending fluid pressure cylinder secured horizontally to the side of the chamber opposite the hinged edge of the door, a piston in said cylinder having an externally projecting piston rod, said piston rod having an exposed end, a locking arm pivoted to said exposed end of said piston rod, a locking bracket on the tree vertical edge of the door lockingly enga-gea-ble by said locking arm, a source of fluid pressure, a fluid pressure line connected to said source, a fluid return line, conduit means connecting said fluid pressure line to the end of said cylinder adjacent the door, conduit means including a manually operated valve connecting said fluid pressure line to the opposite end of said cylinder, and conduit means connecting said opposite end of the cylinder to said fluid return line, said last-named conduit means including a restriction offering resistance to return flow of fluid from said cylinder :to said fluid return line, whereby, with said valve open, a pressure differential will develop in said cylinder on opposite sides of said piston causing said piston to move in a direction to extend said piston rod.

6. In a baling apparatus, a horizontal baling chamber including a horizontally movable ram and fluid pressure means to exert inward force on said ram to compress material in said chamber, a door hinged vertically to the end of the chamber, a longitudinally extending fluid pressure cylinder secured horizontally to the side of the chamber opposite the hinged edge of the door, a piston in said cylinder having an externally extending piston rod, said piston rod having an exposed end, a locking arm pivoted to said exposed end of said piston rod, a locking bracket on the free vertical edge of the door lockingly engageable by said locking arms, a source of liquid pressure, a fluid pressure line connected to said source, a fluid return line, conduit means connecting said fluid pressure line to [the end of said cylinder adjacent the door, conduit means including a manually operated valve connecting said fluid pressure line to the opposite end of said cylinder, and third conduit means connecting said opposite end of the cylinder to said fluid return line, said last-named conduit means including a restriction offering resistance to return flow of fluid from said cylinder to said fluid return line, said piston rod being relatively small in cross sectional area so that there is a relatively small difference in the areas of the working surfaces on opposite sides of the piston, whereby, with said valve open, a relatively small pressure differential will develop in said cylinder on the opposite sides of said piston, causing said piston to move rela tively slowly in a direction to extend said piston rod.

7. In a baling apparatus, a horizontal haling chamber including a horizontally movable ram and fluid pressure means to exert inward force on said ram to compress material in said chamber, a .door hinged vertically to the end of the chamber, a longitudinally extending fluid pressure cylinder secured horizontally to the side of the chamber opposite the hinged edge of the door, a piston in said cylinder having an externally projecting piston rod, said piston rod having an exposed end, a locking arm pivoted to said exposed end of said piston rod, a locking bracket on the free vertical edge of the door lockingly en-gageable by said locking arm, a source of fluid pressure a fluid pressure line connected to said source, a fluid return line, conduit means connecting said fluid pressure line to the end of said cylinder adjacent the door, conduit means including a manually operated valve connecting said fluid pressure line to the opposite end of said cylinder, at check valve in said fluid pressure line located hetween the connection of said second-named conduit means to the fluid pressure line and the fluid pressure source, and third conduit means connecting said opposite end of the cylinder to said fluid return line, said last-named conduit means including a restriction offering resistance to return flow of fluid from said cylinder to said fluid return line, whereby with said manually operated valve open, a pressure differential will develop in said cylinder on opposite sides of said piston causing said piston to move in a direction to extend said piston rod.

8. In a baling apparatus, a horizontal baling chamber including a horizontally movable ram and fluid pressure means to exert inward force on said ram to compress material in said chamber, a door hinged vertically to the end of the chamber, a longitudinally extending fluid pressure cylinder secured horizontally to the side of the chamber opposite the hinged edge of the door, a piston in said cylinder having an externally projecting piston rod, said piston rod having an exposed end, a locking arm pivoted to said exposed end of the piston rod, a locking bracket on the tree ventical edge of the door lockingly engageable by said locking arm, a source of fluid pressure, a fluid pressure line connected to said source, a fluid return line, conduit means including a check valve connecting said fluid pressure line to the end of said cylinder adjacent the door, conduit means including a manually operated valve connecting a point on said fluid pressure line between said check valve and said first-named end of the cylinder to the opposite end of said cylinder, and conduit means including a restriction connecting said opposite end of the cylinder to said fluid return line, said restriction offering resistance to return flow of fluid from said cylinder to said fluid return line, whereby, with said valve open, a pressure differential 'will develop in said cylinder on opposite sides of said piston causing said piston to move in a direction to extend said piston rod.

9. In a baling apparatus, a horizontal baling chamber including a horizontally movable ram and fluid pressure means to exert inward force on said ram to compress material in said chamber, a door hinged vertically to the end of the chamber, a longitudinally extending fluid pressure cylinder secured horizontally to the side of the chamber opposite the hinged edge of the door, a piston in said cylinder having externally projecting piston rod, said piston rod having an exposed end, bracket means on the free vertical edge of said door, said bracket means including a pair of spaced horizontal locking lugs having transversely extending outer edge portions, a locking arm pivoted to said exposed end of said piston rod and being receivable between said locking lugs, vertical abutment means on said locking arm engageable with the outer edge portions of the locking lugs to lock said door when the piston is retracted in said cylinder, a source of fluid pressure, la fluid pressure line connected to said source, a fluid return line, conduit means connecting said fluid pressure line to the end of said cylinder adjacent the door, conduit means including a manually operated valve connecting said fluid pressure line to Ithe opposite end of said cylinder, and conduit means connecting said opposite end of the cylinder to said fluid return line, said last-named conduit means including a restriction offering resistance to return flow of fluid from said cylinder to said fluid return line, whereby, with said valve open, a pressure differential will develop in said cylinder on opposite sides oi said 10 piston causing said piston to move in a direction to extend said piston rod.

10. In a baling apparatus, a horizontal baling chamber including a horizontally movable ram and fluid pressure means to exert inward fiorce on said ram to compress material in said chamber, a door hinged vertically to the end of the chamber, a longitudinally extending fluid pressure cylinder secured horizontaily to the side of the chamber opposite the hinged edge of the door, a piston in said cylinder having an externally projecting piston rod, said piston rod having an exposed end, bracket means on the free vertical edge of said door, said bracket means including a pair of spaced horizontal locking lugs having transversely extending outer edge portions, a locking arm pivoted to said exposed end of said piston rod and being receivable between said locking lu-gs, vertical abutment means on said locking arm engageable with the outer edge portions of the locking lugs to lock said door when the piston is retnacted in said cylinder, a source of fluid pressure, a fluid pressure line connected to said source, a fluid return line, conduit means including a check valve connecting said fluid pressure line to the end of said lastnamed cylinder adjacent the door, conduit means including a manually operated valve connecting a point on said fluid pressure line between said check valve and said first-named end of the cylinder to the opposite end of said last-named cylinder, and conduit means including a re striction connecting said opposite end of the last-named cylinder to said fluid return line, said restriction offering resistance to return flow of fluid from said cylinder to said fluid return line, whereby, with said manually operated valve open, a pressure differential Will develop in said lastnamed cylinder on opposite sides of said piston, causing said piston to move in a direction to extend said piston rod.

References Cited in the file of this patent UNITED STATES PATENTS 566,976 Forder Sept. 1, 1896 1,812,587 Elilis June 30, 1931 2,005,018 West et a1 June 18, 11935 2,219,970 Wallace Oct. 29, 1940 2,241,063 Grimes et al. May 6, 1941 2,503,354 Quinn Apr. 11, 1950 2,576,978 Sward Dec. 4, 1951 2,834,504 Annicq May 13, 1958 3,040,653 Neitzel June 26, 1962 FOREIGN PATENTS 750,042 Germany Dec. 11, 1944 

1. IN A BALING APPARATUS, A HORIZONTAL BALING CHAMBER INCLUDING A HORIZONTALLY MOVABLE RAM AND FLUID PRESSURE MEANS TO EXERT INWARD FORCE ON SAID RAM TO COMPRESS MATERIAL IN SAID CHAMBER, A DOOR HINGED VERTICALLY TO THE END OF THE CHAMBER, A LONGITUDINALLY EXTENDING FLUID PRESSURE CYLINDER SECURED HORIZONTALLY TO THE SIDE OF THE CHAMBER OPPOSITE THE HINGED EDGE OF THE DOOR, A PISTON IN SAID CYLINDER HAVING AN EXTERNALLY PROJECTING PISTON ROD, SAID PISTON ROD HAVING AN EXPOSED END, A LOCKING ARM PIVOTED TO SAID EXPOSED END OF SAID PISTON ROD, A LOCKING BRACKET ON THE FREE VERTICAL EDGE OF THE DOOR, LOCKINGLY ENGAGEABLE BY SAID LOCKING ARM, A SOURCE, OF FLUID PRESSURE, A FLUID PRESSURE LINE CONNECTED TO SAID SOURCE, A FLUID RETURN LINE, CONDUIT MEANS INCLUDING A FIRST RESTRICTION CONNECTING SAID FLUID PRESSURE LINE TO THE END OF SAID CYLINDER ADJACENT THE DOOR, CONDUIT MEANS INCLUDING A MANUALLY OPERATED VALVE CONNECTING SAID FLUID PRESSURE LINE TO THE OPPOSITE END OF SAID CYLINDER, AND CONDUIT MEANS INCLUDING A SECOND RESTRICTION CONNECTING SAID OPPOSITE END OF THE CYLINDER TO SAID FLUID RETURN LINE. SAID RESTRICTIONS OFFERING EQUAL RESISTANCE TO FLOW THERETHROUGH IN EITHER DIRECTION WHEREBY WITH SAID VALVE OPEN, OUTWARD MOVEMENT OF SAID PISTON ROD WILL BE RETARDED BECAUSE OF THE RESISTANCE TO RETURN FLOW OF FLUID FROM SAID CYLINDER THROUGH SAID FIRST-NAMED CONDUIT MEANS CAUSED BY SAID FIRST RESTRICTION, THEREBY PREVENTING SUDDEN RELEASE OF SAID LOCKING ARM. 